Physicist 'spins' mask filters in cotton candy machine
Marie Donlon | November 25, 2020A physicist from the Physics Unit at Okinawa Institute of Science and Technology (OIST) Graduate University in Okinawa, has developed a technique for manufacturing filters for N95-like respirator masks using a cotton candy machine.
OIST physicist Mahesh Bandi heated standard plastic — such as plastic water bottles and plastic shopping bags — and then placed the material in a cotton candy machine (otherwise known as a candy floss machine). Once inside, the plastic is spun into a mesh-like material that resembles cotton candy but that is also electrocharged due to the spinning.
Source: Joseolgon/CC BY-SA 3.0
The material is then cut into squares and positioned close to a standard air ionizer vent to enhance the material’s electrostatic charge.
In the lab, the filters were placed inside 3D printed masks designed in the likeness of N95 respirators. According to Bandi, the filters performed as well as standard N95 masks that feature electrocharged filters capable of capturing viruses — including SARS-CoV-2 viruses like COVID-19 — before reaching the wearer.
Bandi intends to make the plans for developing such filters available to the public in response to COVID-19 global personal protective equipment (PPE) shortages.
The technique is detailed in the journal Proceedings of the Royal Society A.
This report says "standard plastics" which is misleading as there are big differences among plastics, as there are with foods or metals. The public misundertands plastics enough as it is, and such collective use of the term plastics further supports the falsely negative images that now exist. In fact, the author doesn't use water bottles (PET) or shopping bags (PE) as noted here, but rather PP and PS, which both melt around 100 C but don't become spinnable until much hotter, unless solvent-spun (lower temperature but need unpleasant solvents and provision for their recovery). In other words, the candy machine is another device that could be used to make mask material, but not a home DIY project.